In-vivo imaging of animal subjects is a common part of research and investigation of the biological functions of subjects. One advantage of in-vivo imaging is the ability to repeatedly scan or image subjects, allowing comparisons over time as well as comparisons between individual subjects. Repeated scanning of a single subject, or a limited set of subjects, facilitates identification of trends and may be more efficient and effective than single instance scanning of numerous subjects. However, comparison of images can be difficult with live subjects as positions may vary from scan to scan and motion of a subject during scanning negatively impacts the resulting images.
In-vivo imaging typically requires the subject to remain motionless during the scanning process, which can take up to an hour or more, depending upon the number and type of images collected. Injected anesthetics may be insufficient to restrain the subject for the entire length of the scanning process. Moreover, injected anesthetics vary in depth over time, which could effect the very biological functions being investigated. Consequently, anesthetic gas or fluid can be used to provide a constant depth of anesthesia to the subject. However, delivery of the anesthetic gas while the subject is within the imaging system poses its own challenges.
Typically, imaging beds or subject beds are used to position the subject during imaging, providing a consistent platform for the subject. All or a portion of the subject bed is inserted with the subject in place into the imaging system. As used herein, the term “imaging system” refers to any system used for collecting information about the subject. Imaging systems frequently use an isotope to assist in the creation of an image. Some imaging systems currently in use include, but are not limited to, radiological imaging systems, nuclear imaging systems and optical imaging systems, including but not limited to, Positron Emission Tomography (PET), Computerized Tomography (CT), and Magnetic Resonance Imaging (MRI) system, such as the Albira MicroPET, MicroSPECT, Scanlo VivaCT, Bruker and PerkinElmer MR, IVIS optical imaging systems.
Often in research, it would be beneficial to sedate multiple laboratory animals at once; this is especially true in the field of preclinical optical imaging where a control cohort is compared to an experimental cohort. Additionally, sedation of subjects is typically necessary for performance of surgical procedures. This multiple animal sedation is currently achieved in a number of ways, most commonly focusing on the delivery of the gaseous anesthetic to the nose or mouth of the lab animals through individual nose-cones. The laboratory animals are positioned with their noses propped in these cones so that as they breathe, they inhale the anesthetic gas. The fluid or vapors frequently escape from the nose cones, and leak into the atmosphere, which poses health concerns for those working with these systems and the environment.